First off I would like to say thank you to all the people how gave me their input on my last xrap post. But now i have a bit of an issue. I have I belive it is the 8cm xrap. I was fighting a fish today and it felt like it threw my lure so I reeled it in. When I got it in I realized the fish broke the front treble hook off of it. What size treble hook do I need to buy to replace to one that broke since I am going to Bass Pro Shop tomorrow.

Should be a #6 front hook.

Can I replace the front and the back treble hooks with single hooks and keep the performance close to the same? If so which size and kind ( C or J) would be best?

I replace with #4 saltwater on my xr 8, both front and rear and replace using #2 saltwater hooks on my xr10.  No reduction in lure movement at all, use a loopknot.

Can I replace the front and the back treble hooks with single hooks and keep the performance close to the same? If so which size and kind ( C or J) would be best?

Absolutely, common saltwater practice fishing for barracuda, will work for any toothy critter.  I'd upsize the split rings while you're at it. J hook ( siwash preferred ).  I replace the trebles with a siwash on my spoons as well.