Heat Pumps and Electric Heating - '06 mini-split systems SEER and HSPF requirements

I hope this isn't a duplicate question.

In researching mini-split systems I found on toolbase.org that the NAEC Act of '92 requires in '06 minimums to be SEER 13 and HSPF 7.7.

1) is there much benefit to the higher SEER and HSPF numbers
I need a unit soon, should I wait for the "newer" units
2) I couldn't find any manufacturers listing the new numbers
3) I'm installing a unit in a 658 sq' basement game room and the manual J states a 16,000 - 18,000 BTU unit. Is it better to have a unit that is in the 16,000 - 18,000 BTU range or go for a higher BTU unit say in the 18,000 to 24,000 BTU? I thought smaller unit and let it run more than cycle on off with a bigger unit?
4) Which manufacturers have scroll compressors and variable speed?

Thanks,
Doug

I would just go with the 1.5 not over sized for sure esspecially in a basement.

Here is some info that may be helpfull,

http://www.eere.energy.gov/consumerinfo/factsheets/ad3.html

http://www.warmair.com/html/ductless_split.htm