Hi Bill
I hope that by now you have done some searching around the net.
There are plenty of places that will give you an overview of Minolta's AF system flashes.
This is a good one:
http://www.mir.com.my/rb/photography/hardwares/classics/maxxum7k/index.htm
The initial 5000, 7000 and 9000 cameras all used the same "standard" shoe.
The 2800 and 4000 AF flashes are the recommended ones.
Curiosity: the Control Grip CG-1000 set was made mainly for the 7000 and 9000 cameras, but it can still be used with the 7000i and 8000i flashes as they have the contacts on the bottom for it.
Your 7000i will literally use any of the Monolta shoe flashes made for film cameras and maybe even the Sony ones.
I haven't a clue about the current "digi" system.
Any of the i, Xi, or HS will work with it. Special features like Wireless flash will not as only the XI cameras and onwards will have that.
I like my 7000 and 8000i.
I used to have the program Super back 70 for the 7000. Sold it years ago. Have regretted doing so.
One word: the 7000i introduced a feature that has been in all Minoltas since: when you turn off the power, the lens will return to the infinity setting every time. It is a good way for non internal focusing lens to remain at minimum length.