I keep hearing Great Things about The Box of Rocks on the Les Paul Forum.
Mind you.......2 Years ago all you EVER heard about was Mike Fuller's OCD!
I really think that you need to try as many different Pedals as you can before coming to any major decision? I know that it can be hard, especially finding the shall we say....More Exotic Boutique Pedals.
Depending on your style of Music..... And allowing that we are talking about a Peavey (NOTHING Wrong with Peaveys in the main!) I'd suggest trying a few of the more Readily available Units as well as the ones you've mentioned?
A Mate uses a 2X12 Peavey Combo and reckons that he can get a very usable "Big" Sound using the humble Rat. I personally am a Tube Screamer Fan, but then I am NOT a Heavy Player, more Classic Blues Rock. The other Pedal that just about Everyone seems to rate VERY Highly is the Digitech Bad Monkey.
I have used Fulltone Gear and I quite like "some" of Mike's products, but not all. I was so disappointed with a Fulldrive that I moved it out very quickly. I have tried an OCD that a Mate has, now that has possibilities, BUT.......I now see that there is an Upgrade (Version 3) so I have no idea as to what that will sound like?
It's such a subjective thing, I might love something, you try it and find you hate it? I gave up making sweeping recommendations years ago when it comes to Pedals. Bit like recommending a Restuarant isn't it? You go there and have a Great Meal, send a friend who then spends the next week or so telling you all about his attack of Food Poisoning LOL.
So much so........That these days there are ONLY 3 things that I'll openly recommend to anyone.
Bare Knuckles Pickups (Of Course!)
Matamp Amps
Keeley Modded Tube Screamers
That's it!!
Far Safer that way believe me! :D