I need some opinions and some questions answered on a leather or vynal interior job. I dont have too much money so I plan to do it myself if its not too difficult.

How would I go about doing the side interior panels in leather?

Would it be best to keep the roof lining felt or whatever fabric it already is? and could anyone recommend a leather fabric place where I can buy the leather to do all this (preferably one that has a lot of custom colors).

go with vynal alot cheaper
you can do a vynal; headliner also
if your not a good sewer just save the money and have someone do it right

For contact cement, use DAP Weldwood Landau Top & Trim Adhesive.
DAP Weldwood Landau Top & Trim Adhesive 5 gallon (http://www.perfectfit.com/products/shopexd.asp?id=220)

It has a very high heat resistance (upwards of 225-250 degrees) and is very strong. You'll want access to an air compressor and will want a little paint gun to spray it out of. You can choose to brush it on if you like but it will take a very long time, and it tacks quickly so brushing isn't the greatest idea over a big area.

For headliners, regular leather or vinyl is a little heavy, and will start to sag over time more often than not. A lightweight headliner vinyl or synthetic suede like novasuede, ultrasuede make a good headliner, as they are lightweight.

When you wrap something you'll want to make sure it's as clean as possible. Clean it very thoroughly. Strange as it sounds, mixing a washing machine detergent like tide or woolite with water and using that tends to strip all the crap off and clean parts to be wrapped well.

Perfect fit also carries vinyl’s, and some of them aren’t too bad. Don't get your leather from them, it's cheap but it's not good leather. Call them up, they have more selection of vinyl than they show on the website.

SMS Auto Fabrics carries headliner vinyl, as well as more types and colors or vinyl and fabric than you can imagine.
http://www.smsautofabrics.com/wesell.htm

If you call them at all, ask for Doug Pollock. He is among the most helpful and knowledgeable people there. He also happens to be the Owner/Founder.