Not sure what mobiles you are running. but this is what I can say.

Find a GE Mastr exec II mobile and do the full duplex conversion (you can find at repeater-builder) ( I see them on crapbay for as little as $20 sometimes.) for tone (PL control) TS64.
Or bite the bullet and buy an actual repeater GE Mastr II or Motorola MSR-2000 or Quantar (if you are rich) ect.

Antenna get a good antenna. 4 bay dipole or grab a hustler G7-144 or diamond F23H. (if its going to be low to the ground Id roll with a Hustler or Diamond. the 4 bays are 20ft long itself)

Feedline - HARDLINE HARDLINE HARDLINE

using junk radios for the repeater or a junk antenna or junk feedline will make the repeater useless. So bite the bullet and just get the good stuff right off. and you will be much happier believe me.