I just found a site that has a page arank of 4 on 4 out of 5 pages they have 800+ great linkbacks pr 7 pr 8 and a few hundred 0 They have no lotgoing links what so ever So would a link from here be enough to get a site indexed and pr????
Indexing happens regardless. PR is calculated periodically. And alot would depend on the niche of the other site, is the link "valid", how many other links you have...
Enough to get indexed (but this is really easy), but you need more to get decent PR. It depends mainly of amount of outbound links on that site.
Who told you that you need 800 + PR 7 and 8 to get just PR 4.. I am sure you can get PR 5 or 6 atleast with this.