Recs for IIGS Expansion cards?

That totally depends on what you want to do with it. The IIgs is loaded with all the basics, so most any card you would be adding outside of mass storage (which you already have) would be for an edge case.

The only one I would really recommend is a stereo card. It's completely slot independent as it only pulls power from the slot, no data. There are modern reproductions avaialable, like the Lite Sound. Unfortunately it's out of stock. But you can sign up for alerts when they are back in stock. Last I heard the creator was working on making some more.

Note, this is a stereo card for IIgs software using the Ensoniq chip. It's not going to give you mockingboard support for 8bit software. Which you could get a mockingboard clone if you really wanted to. But the pool of software that supports it isn't that large. 

...that the IIgs has built-in I/O such as the two serial ports, the mouse, 80-column mode/memory expansion, floppy controllers, etc.

So, to use any of the predefined slot assignments for these built-in devices that are memory mapped for a given slot, you must disable them in order to use them for something else.

Since you are using slot 7 for SCSI by not using AppleTalk, slot 5 and 6 can be reappropriated easily if you aren't using the 5.25 or 3.5 floppy drives.

IIgs_Slot_Register_Assignments.jpg

But maybe you already know this.

That's a little bit misleading. For example, you can use built-in functionality like both serial ports and have cards in Slot 1 and Slot 2. You can only have one set of $CnXX firmware active, but that doesn't stop you using serial ports and cards at the same time. Same with the mouse - putting a Mockingboard in the Mouse slot does not stop the mouse working in GS/OS!

To answer the original question. First item would be an accelerator card for most IIGS users. The only people who wouldn't put an accelerator card first are people that just use the IIGS as a 8-bit machine only. Other card choices are purely based on your interests and will be different for different people.

Before investing in cards, especially in not so useful accelerators, I advise you to play with one of many //GS emulators (you are blessed you live in time when they are available, not like in the years when //GS was released) and see what will suit your needs. These emulators are also able to run at accelerated speeds. 

Austin_iigs wrote:

I was thinking the 2soniq stereo sound card. Is there any reason why the Lite Sound is better?

It's almost half the price? A 2soniq runs around $70-80. A lite sound is like $43. They both do the exact same thing, you aren't going to notice a difference. Plus Bob Darlington is a good guy. Not to say whoever is behind Manila isn't. Just all my interactions with Bob have been positive.