Many mail order houses for vinyl these days, also you can buy albums by the groups you list in good condition used from time to time on this site, also check eBay. Some new music is also issued on vinyl, but not by the groups you listed (obviously). Websites for good new heavy (180 gram) vinyl were recently posted in a thread in this forum, so check the search function for those posts. Music Direct at www.amusicdirect.com has many labels and good prices. Better Records out of Chicago does too (also a mail order outfit). And you can always start combing through the old used record stores, full of dust and gems. You can find one or two in most cities you happen to visit, it's fun to go looking for both the stores and the LPs.
Good luck and happy hunting!
Good luck and happy hunting!