I enjoy wrist-braced slingshots and have several classic wrist rockets (Trumark, Barnett, and Marksman) as well as a custom arm braced slingshot from A+ Slingshots.
Trumark is my favorite classic wrist rocket. For target shooting, it is difficult to beat a Trumark FSX 2000, with innovative rotating band posts, a fiber optic band alignment system (often mistaken for sights), and even stabilizers. I also enjoy WS-1's and FS-1's. The wide forks on Trumarks are very forgiving. Unfortunately Trumark is no longer in business.
Marksman slingshots have narrower forks and do Barnetts. They are very serviceable and a great bargain. You can pick them up at many big box stores, including Wally World.
I also modify non-wrist braced wire-frame slingshots to shoot paintballs with kids.
As mentioned, cut off the tubes and pouches and install a good bandset with either flats or narrow tubes. There are instructions here and on Fowler's and Pocket Predator's web pages about this. Pocket Predator sells a nifty adapter for this purpose. I wrap and tuck the band set onto the wire frame.
My custom arm-braced slingshot from A+ is built on its innovative Wolf Claw arm brace. It extends midway on the forearm and is very comfortable. I have one frame for shooting 1/2" ammo (Perry recommends 1/2" steel shot, 5/8" marbles work great) and another for launching golf balls for distance. I actually play golf with it.
SimpleShot's Hammer is offered in several iterations. The XT model is designed for a wrist brace. There is all sorts of information on its web pages.
I've used a Barnett's black widow and a Daisy B-52 (I think). They were both solid frames, but I did like the ergonomics of the Black Widow handle better, and the lower forks mean less stress on your wrist. They all seem to be pretty standard in terms of quality and usage though. As others have mentioned, the tubes and pouches aren't great, so you're really investing in the frame itself. They all seem to be pretty equal, although the Barnett Cobras do have a cool looped fork.
The one thing that would make one really stand out is an offset wrist brace that was adjustable to R or L hand shooting. Aside from that, I think Blue Raja has the right idea. Buy a frame and then make custom modifications to tailor it to your needs. Best part is, most are about $10 - $15 at Walmart so if you don't like one you're not out much money.
My favorites are two diametrically opposed models the Tru Mark WS-1 and the Saunders Wrist Rocket Pro. I like the Tru Mark for sentimental reasons, the fact that the tubes last forever and is actually a pretty accurate shooter, the Saunders because it looks cool and is very accurate, but is on the expensive side.