2 places i know you can get from....
MGS2U
&
Gunplastore

NOTE: Both are selling Recast...

aww... that's too bad... i know they usually don't keep stock so u'll have to order from them...
Those are the 2 that i know that are selling though if you don't mind the original resin ones which will cost a bomb.. haha

it's actually original brands... haha
neograde from Hong Kong
Vicious Project from Korea
there are few more popular brands but i don't remember the names

Correct me if i'm wrong..

You could ask chriswoo since he bought the ori ones 

Dreamcast is actually a recast brand...
from what my friend told me, recast brands use originals(neograde,VP) and modified a little or more and then recast it to avoid trademarks or something like that from the big brands...
for the price, i am not sure whether they are similar anot..

haha well actualy most of the time i buy resin recast version only due to the original was sold off long before even i started the kits. 
well as i can say if you want to play with resin kit you need to be very experience on it especially your basic modeling skill as well as your coloring skill. with out those 2 skill achived. I recommended you stick to the plastic for now. Or you may end up wasting your time, money and your material as well.

other thing i like to point out is when you buy any resin kit no matter wat brand ( recast or original) you need to place your luck on the casting manufactering company. because even the original casting also have few defact parts (properlly very rare case) but mostly of the original company can replace for you in no time due to the reputation but for other recasting company you may face alot of defact parts.

example like my current project sazabi conversion kit from neograde was recast by hobbyfans and I can say the quality casting is lucky quite ok with it but I need to also fully recorrect every inch of the surface and panel ling to get my sastifactory desire. This is also due to I also delay this project for a year to improve my modeling skill.

here is the picture sample





as you can see those quality casting is really nice but also need a lot of touch up to make it better and smooth.

and here is the result of a year experince i had so able to achive this result.



so in conclusion. learn the basic skill before trying out the advance type of modeling. learn to walk 1st before can run.