i have an 87 cherokee 2 door sport. 4x4. I was wondering if anyone has used rhino liner instead of paint. and if so about how much?  

I used dupli colors truck bed liner on the outside of my old yj. It cost like $50 and held up good for over a year, then i sold it. Make sure you scuff your old paint realy good or it wont stick. I used 80 grit sand paper. Ill see if i can find a pic.  

i also had a yj (1990) and didn't even bother sanding down the old paint job. I didn't even use rhino liner. I just went down to the local auto zone and grabbed about 10 cans of the cheap bed liner they had and went with that. This sounds extremely ghetto, i know, But it worked. My buddy did his tj with herculiner and did some actual sanding, came out great.  

durabak, is the *** this stuff is very durable i put the rough coat on my 94yj it will take the bark off trees and leave no damage to your jeep. its $80.00 bucks a gallon comes with a roller and pan its worth every penny. i  did mine to years ago , one of the best mods soofar.  

I used Hurculiner on the rockers of my 79 cherokee,2 coats and 2 coats of it on the floor on the cher too. went on great and the kit came w/everything you need for 99$  

Ok so how will all these products work on my hard top? It looks raggedy and I've seen painted ones that don't look so hot.  

If you clean the top up really good and prep it right, then whatever you choose to put on it should look good and protect it against the elements. mind you that if you use something from a can then apply at least 2 coats.
Theres an area on my rockers on the rr of my jeep that has a dent that couldnt be taken out and I cleaned it up the best I could (dont believe in body filler) and the hurculiner stuck great and looks good too even though its smashed!  

Oh by the way way my 3 year old likes your avitar. He tells me "look daddy funny boobies".LOL. How do you suggest preping the fiberglass?  

maybe use a medium steel wool. you want it scuffed enough to hold the product  

The steel wool like chariot suggests or I use whats called "SCOTCH-BRITE 07447 general purpose hand pad" its 6"x9" and 1/4" thick and scuffs really good.Dont do it too hard cause you dont want divots in the -glass.