Need some help on a crt .5 conversion

Hey guys!
New to the forum and have a few questions
Ok to start with I got a brand new crt .5, a brand new VXL brushless system, and a brand new spectrum MG servo for steering. The truck also came with the rc-monster motor mount. Everything is still NIB ...I don't think I did too bad considering everything is brand new and I paid 300 for it all

ok now while I am not new to brushless I figure I would save myself some headache and ask the people who know and have done it.
To complete this truck I need the adapter to convert a 5 mm bore pinion to 1/8 inch shaft (vxl) correct? I know I saw it on here somewhere....
Also I need a someone to recomend a pinion for this thing......should I start with what is stock for the nitro motor? 13 tooth I believe? Do I use the mod1 pinions? The pitch is kinda throwing me for a loop and I am not sure what to get. I planned on getting a variety of pinions but I need somewhere to start first.
I have 3300 Mah 2 cells and 3300 Mah 3 cells
I also have many 2200 Mah 3 cells

I know the VXL is not the first and best choice but it's what I got so I would really like to use it

(I tried using the search function but couldn't get desired results)

If anyone is able to help I would much appreciate it!
Thanks!