I thought I'd share a brief list of the equipment that goes with me cave diving, while mentioning good (and bad) things about the specific brands and mods I've chosen.
Wetsuits
Caves in Mexico are typically 75-77 degrees F. I layer two wetsuits: a 3 mil full length Henderson and a 3 mil shorty Mares. The Mares has been with me my entire 9 years of scuba diving and it's still in incredibly good shape. Henderson is crap/cheap dive gear, this is my 3rd piece and probably my last. They just don't keep up their thermal properties after 100 dives. My plan now is to get one of the new WaterProof W1 front-zip 5 mil wetsuits, as soon as they come out next year.
Regulators
All 3 of my regulator sets (2 x DIN for doubles, and 1 x Yoke for stage tank and open water) are Atomic Aquatics B1/B2 sets. All were purchased off eBay for really good prices. I've had minimal problems with any of them. Performance is as good as everyone says. I highly recommend Atomic Aquatics.
On 2 of the 3 second stage regulators I have a SeaCure mouthpiece. This is made of a special plastic that is made moldable when exposed to very hot water. In this way you can customize it for your mouth the same way that wrestlers' mouthpieces are molded. It adds a LOT of comfort to the regulator, and I find my jaw almost totally relaxed when diving with it. This is extremely important in cave diving, when you want to be 2 or more hours at a time breathing off your regs.
Lights
My primaries are a Dive Rite H10 10 Watt HID and a Dive Rite 500 Lumen LED. I now wear both when cave diving so I have a primary primary and an alternate primary, in addition to my two backups. The H10 has been good to me but lacks the power I desire for cave dive videography.
During all last week I was using Sandra's 21 Watt Sartek, usually instead of my H10. But sometimes I carried both the corded HIDs. The Sartek was sometimes difficult to get lit, either the battery connection would be loose or there would be a problem with the switch. But once running it was a fine piece of equipment. Until the 3-year old batteries died. The light would suddenly start to flicker, go blue and purple, then dim quickly. From flicker to dead was only about 45 seconds. Not much warning! I always had an alternate primary so it was not much hassle. It died on me in Labna Ha, Dos Ojos, and Pet Cemetery. I never once had to resort to my backups.
I'd like to upgrade to a 35W or 50W model HID (probably not Dive Rite) but LED technology is catching up fast. That makes purchasing decisions on a new light rather difficult. If Salvo were still in business I'd be buying their 35 Watt HID light about now. As things are, I don't know what light I'll be diving with a year from now.
Fins
The two most popular models of fins among cave divers are Jet Fins and Mares Quattros. Sure, there are others used but these are the two I see most often. I am a dedicated fan of Mares Quattros both for cave and open water. My fins are configured with spring heel straps. I recommend spring straps for ANY fins used for ANY kind of scuba diving.
BCD/Wing
Dive Rite Transpac II with Rec Wings (51 lbs lift). I like this combo because it easily configures for both single and double tanks so I only have to carry one BCD for both cave and open water.
Computers
My primary computer is now the Suunto HelO2, so I can change gas mixes during a dive. Definitely important when staging bottles of Nitrox in cave diving! The HelO2 has a radio transmitter so I have one less hose to tangle me for open water. For cave diving I use a regular SPG (standard pressure gauge) in addition to the radio transmitter, for redundancy. I find myself almost never looking at the SPG. The exception was when I used Sandra's 35 Watt Salvo. I think the high-frequency ballast in that particular light interfered with the receiver. The only way I could get tank pressure on the HelO2 was to hold my right arm behind my back, away from the light head in my left hand. During that dive it was inconvenient to hold my hand back there the entire dive so I just used the SPG instead.
My backup computer is a Suunto Vyper which has also been with me for all nine years of my diving. It became my primary computer for only one dive this week, at Tux Kubaxa, because I accidentally left the HelO2 back in my hotel room that morning.
The HelO2, the Cobra it replaced, and my Vyper all have a user-replaceable CR2450 lithium battery. Replacing the battery myself instead of sending the computer in for service has saved me $tons$ of money. Sometimes, though, CR2450 batteries are hard to find in resort locations.