I had a prosport Boost gauge before and it was okay, although i have heard a lot of iffy stories about them, especially the oil pressure ones.
Heres is a link to a 60mm gauge that i think is a very tidy job, especially if you dont want 3 and 4 seperate gauges..Boost, oil temp, oil pressure, volts.
http://www.ebay.co.uk/itm/DEPO-RACING-60mm-White-Gauge-4-v-1-Oil-Pressure-Oil-and-Water-temp-Volt-/110965894410?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item19d6152d0a
Heres is a link to a 60mm gauge that i think is a very tidy job, especially if you dont want 3 and 4 seperate gauges..Boost, oil temp, oil pressure, volts.
http://www.ebay.co.uk/itm/DEPO-RACING-60mm-White-Gauge-4-v-1-Oil-Pressure-Oil-and-Water-temp-Volt-/110965894410?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item19d6152d0a