904 tranny questions

I pulled the valve body off of my 904 tonight to put on a cheetah reverse pattern body, I didn't pull it completely apart but was noticing that it appears that there isn't much meat left on the bands. I was suspicious of this as the guy I bought the tranny was real sketchy on how many miles were on it since the "rebuild". My 360 mag is already going to have about 350 hp and the nitrous will add another 150. Instead of worrying about it I have decided to get it rebuilt. My questions are where you recommend getting a rebuild kit from. Looking to get quality parts for a reasonable price. I have a friend who has a 5800 rpm governer out of I think an old max wedge tranny that I want to get which will settle the shift point question. What I need to know is can a good trans guy build it to have really firm shifts without getting a shift kit, or do I need to get one. I was thinking about the trans kit that gives it really firm shifts and you can hold it in any gear as long as long as you want, but can't remember the name of it. But I really like the stab and steer it idea with the 5800 governer, a little advice here would be greatly appreciated.