See GPS Module with Antenna . My doubt is whether the module specified here will exceed the current limitations of RPi, if so how can i interface this to RPi? what is the current rating so that i can use it on Pi without fuss. can i use emitter follower configuration of bjt to boost up the current to meet the gps module' current requirement?
regarding the GPS module, please, see my comment above. BU-353 is cheap, reliable and proven to work. interfacing something else with TTL level shifters from 5V to 3V3 and back is troublesome and eventually will lead to pain and frustration, possibly including burnt unit and/or RasPi.
Raspberry Pi has no output power limitations. There's a polyfuse, that limits the total current to something about 1.2A, thus, considering RasPi consumes about 0.7A, you have about 500mA to play with (~10 times what you need). Still, if you shorten the polyfuse and attach a good power supply you may easily pull the current in excess of several amperes, provided the PCB traces won't burn.