Hi Graham and welcome to one of the most friendly sites on the web.

I am a long time users of Band-in-a-Box (BiaB) and I agree with you in that the packages PGMusic sells is very confusing. The main thing to remember is that the main engine is the same in all packages; thus the least expensive Pro has the same BiaB engine as the most expensive. The difference is in the amount of styles, both MIDI and Realtracks, as well as the number of Super MIDI tracks. This page shows what is available in each package, just scroll down; this assumes you have a PC, if not look at the Mac packages:

https://www.pgmusic.com/bbwin.packages.htm

I suggest you get the biggest package that you can afford. If possible I personally suggest getting the Ultrapak. This will give you everything that is included with BiaB. Also it is cheaper to purchase this then to purchase a less expensive package then purchasing extra Realtracks and Realdrums.

Also with the PC version you get RealBand, a DAW, for free. This may or may not interest you right now but I may come in handy later.

If you haven't already go over to the showcase forum and listen to some of the music that has been generated by BiaB.

I hope this helps

My goal this weekend is to move just enough each day so that no one pokes me to see if I'm dead or not.

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware