I had an SPMotorsports intake tube.. but I later replaced it with just a silicone hose.
Coolant temp gauge: Look under the throttlebody. You'll see a sensor screwed into the side of an aluminum coolant tube. The sensor that's there is for the OEM temp gauge. I bought a T and different sized fittings to keep my OEM gauge... but next time I have time, I'm going to pull the OEM sensor and T, and just install the aftermarket sensor there. Here are two options, and I would highly recommend the Ace hardware off 35th Ave & Beardsley... they have a HUGE selection of piping, which Home Depot and Lowes did not. I'm also assuming your aftermarket sensor is 1/2".
1) Get a 3/8 male -> 1/2 female adaptor and eliminate the OEM sensor.
-or-
2a) Get a T (1/2 female all around)
2b) a 3/8 male -> 3/8 male adapter (forgot the proper term), this connects the coolant pipe to the base of the T.
2c) a 3/8 female -> 1/2 male adapter, this connects the OEM sensor to one of the long sides of the T.
2d) the 1/2 aftermarket sensor will just screw into the other long side of the T.
Don't forget teflon tape on either of these options!
Oil pressure gauge: Seems that most people use a port behind the a/c compressor. I have a relocated oil filter and have temp and pressure sensors attached to the filter adapter base. I prefer the relocated filter.... and it was a piece of cake for the sensors.
Oh.... getting them through the firewall is a little more challenging. The best place I found, for 3 decent sized holes for the big grommets, was right above the fuse block under the dash. The holes will enter the engine bay right under/behind the cruise control module.
If you want, we could meet up so you can see what I'm talking about.