No way would I do both at the same time. You'll sweat blood trying to figure out if your sql conversion was broken or your 7.6.200 install was the problem. I have installed 7.6.200 about 8 times now, mostly because I had payroll. All btrieve sites have problems, many are remedied through a number of support calls & many downloads. I have about 15 patches that I regularly install & just keep getting more as I go as users report other broken code in modules some use & others don't.
MRP still seems to be broken. I know of at least 2 sites still having regen or reporting issues, including one of my own that I am trying to fix in order to migrate to SQL because they fixed some broken stuff w/bins & lots from the 7.6.100 code. Of course, we use lots & bins, both, so we could be beta testing for all I know, since I haven't yet been able to regen this site using the pervasive 2000 client. Naturally, I'm having to go all the way from NW4.11 103f (all unsupported including win95 clients) all the way to sql 7.6.200. The only way I can do this w/o a spare workstation on site is to run psql WS & MSSQL server on the MSSQL server until I am able to perform a conversion. I've tried to configure electronics to be like my real client data & can regen there, but not with live data. It su$$$. Pardon my French.
I hope you are planning a test conversion before you go to sql. Make sure all your master & history files convert the same data from btrieve to sql. Also, make sure all your accounting & month end reports tie out before a final conversion. Once you are done with sql conversion, I would apply the 7.6.200 update since I, at least, have had less trouble w/sql installations than btrieve going from 100 to 200. I think Macola just didn't test the btrieve as aggressively as MSSQL since the OEMs & resellers have given in to Uncle Bill or have become true believers.
If you have a local reseller, you should be able to get a 7.6.100 conversion going for btr2sql. You also need to make sure all workstations & servers are state of the art & patched to current. Don't try to put 200 on anything more than a year old. You're asking for trouble.
SO:
Get your hardware up to speed
Get your OS patched/up to current
Toss out those dot matrix printers
Convert to sql, verify & run through a month end
Get all available patches & read all 7.6.200 infomines, hot fixes.
Prepare your users for the fact that printing may be a serious problem for a few days while you get any fixes no one else has already found for you.
Figure out if you use crystal if you need to upgrade from 7 (or earlier) to 8.5.
Be sure you know if you have custom cobol mods or custom programs that need to run off the new dll format rather than the old compiled lbr format.
If you use TS win2k 2003, you really need to test your Macola behavior. Many posts here relate to win2k TS that seem to resolve in win2003, but I have found other things problematic in win2003 TS that I am still working through.
Upgrade to 7.6.200.
Tell the owner of the company he owes you a week on the French Riveria w/no cell phone once you complete this project: all expenses paid.