Submersible well pump sizing

I am replacing the two pipe jet pump I have now with a submersible pump at our home. It is a 60' cased well in a pit. I will be adding a pitless adaptor and a well extention to bring it above ground. Ive read a lot about sizing the pressure tank for draw down and pump cycling etc so Im pretty good there. Here are my questions.

What is the difference between a 110 and a 220 submersible pump in this application providing the GPM are similar. Is one prefered to the other, longevity, cost of use etc?

Currently Im getting about 1 gallon a minute out of my kitchen faucet with no aerator and about the same on teh second floor shower with no head. What is a typical flow from these?

Is there big difference between 30/50 and 40/60? currently I have 20/40 and its a not muc more than a drizzle in the upstairs shower.

Any recomendations in this case? 3 bedroom house two bath and I will be installing a lawn irrigation system in the future and a whole house active carbon filter to remove the small amounts of radon we have. I was thinking a 7 or 10 gpm pump at 40/60 with the appropriate pressure tank for draw down and 1 minute or more between cycles...

Thanks gang

noone has any thoughts on this?

I am basically taking crash courses on wells, pumps, and the related due to necessity so let me pass several sites I ran across with helpful info.

http://www.aquascience.net/submersible-pumps/. There is a box called helpful info with links. Check that out. It has some calculation tools.
http://www.pumpsonline.com/FAQ.htm
http://www.flotecpump.com/ResidentialProduct_fl_hw_4S_FP2232.aspx Look down in specifications and resources for some good general info.

There are a few other sites that I can't find the links right now, but this may provide some helpful info.