The difference between a Phenom and a RageX is in the strength curve needed to run them. A Phenom uses a more elastic material, so that it supports you less at any point, but actually gives support through a longer range of the motion. A RageX uses a stiffer material that will give you more support, but it is focused on the lower half of the movement. Denim is stiffer yet than PGX, gives you even more support at the bottom, and leaves you even harder at the top.
Basically if you can lock out a lot more than you can bench you should use a RageX. If you need more support at lockout, then a Phenom may make more sense.
Common wisdom has it that with proper training (boards, bands and lockouts) most people will lift more in a Rage than a Phenom, but there are notable and significant exceptions like Mr. Rychlak.
The problem here is that when you go to upgrade, you are going to have to try some reps in a few different shirts and see which one suits you. Finding a shirt that suits your style, fits well without too many alterations, and provides support where you need it is really the hard part. When you put the ?Right? shirt on, you?ll know.
If you can find some other lifters near you, around your size, ask if you can try a few reps in some of their gear. You will be surprised at the number of shirts most of us have tried, and have kicking around, and most are more than happy to see our Big Box of Unused Shirts get used to avoid the stumbling around that we had to do.
This clumsy, trial and error, process is why you can often find good, used, equipment, cheap.
If it is legal in your federation, I highly recommend using an open-back shirt, with a belt. It is really that much better. Just be careful with an open-back blast, as they are vulnerable to blowouts.