Looking for SEO software & question bout PageRank

What would be the best and preferabbly affordable software to get for doing
initial site submissions plus has ranking tools, keyword & meta optimization
tools, basically something that does it all.


Also I was wondering, if anyone might know teh approximate number of PR4
backlinks it would take to get a PR4 yourself, or do you need PR5's to get
to PR4... I dont totally understand how PR works yet, so if i sound a lil
dumb on the above, well I am.. lol