Lots and lots of choices, and many people will just recommend what they have, which gives you a pretty good indication that almost any reg made by a reputable company will work fine. I think it's fairly important to know how and where you will get service on the reg before you buy, so if you have a LDS that you like and feel that they will do a good job servicing, then you can buy something from them. Just don't get talked into a high end reg; and if they even insinuate that the higher end regs are safer (isn't your life worth....) then walk away and find someplace else.
I wanted to buy a reg right after my OW course, so I bought the low end SP MK2/R190 on the advice of my instructor. I have a feeling he got chastised by the store owner for not trying to sell me a higher end reg, because the owner (incredibly enough) seemed a little steamed that I wasn't buying a MK25. Anyhow, the MK2 has worked great and I still have it, although I rarely use it because I have a bit of a "problem" with older SP regs. The problem is I buy them and tinker with them.
I'm not too familiar with the brut, but sherwoods are generally unbalanced piston regs like the MK2 and have the reputation of being very simple, reliable, and easy to service, all good things.