Simmo,
Love the idea - I keep thinking 'pimp my scope'
Here's what I've found while I've been using my 8" dob with 2 eyepieces (a 25mm and a 10mm) for the last 3 years.
I've needed nothing else except Stellarium and some good charts (Taki's free one is excellent).
But now that 3 years have passed I'm starting to get serious, so here's what's on this years Christmas list
A red dot finder, using the 8x50 is fine for the 'brighter' stuff, but a 'straight thru' is going to be much easier.
A 8mm to 24mm zoom eyepiece (about $70) a cheap way to determine what focal length I feel works best for me and the scope before I spend hundreds on that one (or two) special eyepiece
A 32mm 2" eyepiece, for those DSOs that are just too awesomely big for close ups
A 2x barlow. I don't plan on using this much,
but for the kids - getting things as big as they can (jupiter, mars, SATURNs RINGS, etc.) gives the WOW factor (put stickers on the scope too for the kids!!)
REAL Thermal clothing, but I am in Canberra
And last but not least a 12" dob - like I said I'm getting a bit more serious (even moving house to a darker site away from the city!!) and like they say 'size matters!' - but for a first scope the 8" has been perfect.
VAZ