A Couple of Questions

Hi!

Let say I'm composing a song in C major, using a I-V chord sequence in root positions. The bass is playing C under the I chord, and G under the V chord.

Now, for a couple of bars i want to play a little higher up on the keyboard. What are my options? and what is the most common thing to do? Do I:

a) invert the chords; playing in first inversion.
b) transpose/modulate to another key
c) any suggestion you might have

Also, if I chose to invert and play in first inversion, how can I "move" the bassline so that it follows along with the harmony? Shoud I play E and B, which are now the bass notes in the harmony?

//SFG