Keeping a 2006 Giant SCR 3 on the road - 9 speed to 11 speed? I have a Giant SCR 3 which was a freebie from a mate, who had it new.  It's approx a 2006 I think, and I've had it about 5 years.  I've spend a relatively small amount along the way at the LBS, keeping it going.

Due the serious mileage it's seen between the two of us, the following are now clear;


The original Tiagra 9x3 groupset is nearing End Of Life (confirmed by friendly LBS, who don't try to sell me anything I don't need)
The original Alex rims are WAY beyond the wear indicators, although, nothing bad has happened yet!
Braking is now a serious effort on the hands (needs new cables I guess)


As much out of nostalgia for my first decent road bike, I'm tempted to give it a new lease of life.  I have other bikes, but this is/was my go-to commuter, and old enough to lock up in town on a night out too.

I believe the 9 speed is now obsolete in Tiagra?  So do I go Sora 9 speed (Sora in 2019 perhaps similar standard to 2006 Tiagra?) 
OR, as I need to change wheels too, is this an opportunity to go to new 11 speed Tiagra?

Am I missing a trick here? Can I just by new cassette, chain-rings, chain, and keep it going...

Thanks all

James

PS: Little bike DIY experience to date, although I am mechanically minded.
I think your minimum refurb to bring the bike up to a good standard would be: new wheels; bottom bracket, chain, cassette and chain-rings; housings and cables (shift and brake); tires, brake pads, bar-tape; and a total, thorough cleaning and re-adjustment. This is assuming the derailleurs and shifters are actually working OK, and your LBS just means 'obsolete' when they say they are at 'end of life'.

That's a fairly big chunk of the bike, so you may want to go the whole way and upgrade the groupset. Personally I'd want at least 10 speed as an upgrade - Current Tiagra 4700 is 10 speed. Another option is looking for lightly used 105 5800 or Ultegra 6800 (or perhaps even R7000 or R8000) 11 speed components.

I'd look for a good set of lightly used wheels. As tech has moved to disc brakes and thru-axles you can probably find some really good light and strong rim/QR wheels for reasonable money.