Many thanks to this wonderful Dell forum, I examined closely the eBay listing before I bought the Dell 1121 (11z) Sprint version - Intel core i3. Because of this particular thread, i realized that there is no bluetooth. NOT good for me.
Before I received the Dell 1121, I already had the 4gb ddr3 ram and the
DELL DW1702 FJJTN Wireless wifi N & BT
3.0+HS Card waiting to be installed. the 4gb ram was purchased from newegg and the wifi + bluetooth from eBay.
the dell 1121 came in brand new and sealed. it did not see a first boot. i opened it up, took out the mechanical hard drive, used easeus partition software and shrunk the partitions so that the dell diagnostic partition (100MB), the recovery partition (12GB), and the OS partition (win7 64bit - 23gb) totaled 35GB. the rest of the hard drive over 200GB was unallocated.
i booted ultimate boot CD, used acronis to copy the 3 partitions to my ocz 40gb vertex 2 ssd
(which was taken out of my old samsung nf310). used bartpe and bcdedit from another win7 machine (32bit) and configured the bootmgr (residing on the active partition - recovery partition)
installed the ssd
and replaced the wifi/wimax with the wifi/bluetooth card.
voila! i booted successfully to a dell factory image of windows 7. uninstalled as much bloatware i can find, transferred my data, configured the wifi, and bluetooth. tested the bluetooth tethering to the nokia 5230 (all good - even using it at this time). tested connectivity to jabra bluetooth bt2050 (all good - i use this everyday for google voice).
i recommend the dell dw1702 wifi and bluetooth. the drivers came from the dell website (i think vista drivers). a little quirk - when i'm talking on the google voice, sometimes the volume would turn up very high on my end, but normal for the other person at the other end of the call. i fix it by muting and unmuting. dunno if it's the jabra or the bluetooth module that's having the problem. it happens very seldom and the fix is easy to do.
bluetooth range is easily over 20 feet, as i was able to carry a conversation while going to the kitchen and the dell 1121 is at my desk (this is at work).