I want to fit a volt meter, electronic oil pressure guage to my ba any special tips or is just a matter finding the right power wires and splicing in.

I've got that exact setup in my BA XR6, Autometer Voltmeter/Oil Pressure gauges in Cobalt range. Looks awesome at night time with blue backlight and dark orange needle, matches the cluster a treat.

There's no real special tips per se, just be prepared to dismantle your dash and get your hands a bit dirty. Voltmeter is very simple to install. Oil Pressure is a little bit more work, you basically need to install a splitter onto the pressure sender that is used for your cluster (the light which illuminates when pressure gets too low).

There are downloadable PDF instructions on the Autometer web-site for installation instructions, and plus plenty of threads on this site too.

You can also just run the sender to an oil filter adaptor instead

moot, i did similar to mine. to do the oil pressure, i pulled the stock pressure switch from the block, added a 't' piece i got from couplers for $5, and screwed that in. put the stock sender back on and added the gauge sender. if the gauge sender is 1/8npt, then ive found you can use stock aircompressor line fitting to extend the coupler for clearance. voltmeter is a piece of piss. ran the wiring through drivers firewall, and up the back off the icc.