m42 to infinity?

Hi Folks,

Is there an m42 adapter mount that will let you focus to infinity? I'm doing some research here and read a few posts on dyxum on the matter, but it's confusing with all the different makes.

Lets see...there are a few adapters to link to:

Jolos:
http://rugift.com/photocameras/minolta_af_lens_adapter.htm

I'm told this is too tight on the 7D but works on other film AF cameras..can anyone confirm?

Generic (@ B&H)

http://http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=97558&is=REG&addedTroughType=search]

One report implied this wouldn't focus to infinity?

Technik (Ukraine)

http://http://cgi.ebay.ca/Pentax-M42-Lens-to-Minolta-AF-Dunax-body-adapter-NEW_W0QQitemZ7570466421QQcategoryZ30059QQssPageNameZWDVWQQrdZ1QQcmdZViewItem]

Haven't heard much about this specifically.

Do any of these focus to infinity? Any comments on which works better? I've got a couple of SMC Takumar prime lenses (50mm,300mm) that I would love to play with.

Thanks,
Damian