Welcome ...
Makes sense to do the things you have planned.
But on the waterpump, I wouldn't bother doing it just for the sake of doing so.
It's an easy job, no matter where/when/what you have to do, but for the sake of peace of mind, have the pump in a spares kit.
The only caveat with the water pump are the notorious 3 long bolts along the left hand circular section. I think 5 or 6 bolts on the longer straight neck shape on the RHS, are all shorter.
But the longer bolts will probably have rust on the shanks. In itself, not a problem, just can be hard to remove, but some have had the issue that they rusted so much, they could shear due to bad rust, or the rust locking it harder than normal when removing.
So the recommendation would be that if you do get a pump, irrespective of if you do it immediately or hold on to it as a spare part, remember to get the 3 long bolts for it too.
As for gauges, definitely get the coolant temp AND EGT gauges ... both handy to see in real time how the engine is running. As anomalies surface, adjust your driving to suit ... 
Also, depending on how you like to set yourself up .. there are options for gauges that end up looking less dramatic on the old dashboard.
So instead of having a gauge for this, and a gauge for that .. etc. you can get systems that show you multiple gauges on a single screen of some type.
My fave is the 1Gauge(that I have), but there are others too like the MadMan gauge system. I preferred the 1Gauge for both lower cost and nicer screen .. do a search for my thread on it to see what I mean.
Price on the 1Gauge has gone up since I got mine tho ..
There are others too, just can't recall the names/brands now.
But, the point is, if you think you'll end up spending say $300 for gauges(and don't be tempted to get really cheapo cheap Chinese unknown quantity items too!), maybe spend jsut a little more and have say 7 gauges all up instead ... but remember that's on a single screen!
D1 looks really nice too .. and damned! ... I wish I had a grandma like that too now! 
Is it auto or manual?
(maybe put it in your sig, so that when you ask a question for something or other, folks will read it and know better how to respond too)
Cheers,
Arthur.
'99 D1 300 Tdi Auto
Bookmarks