Lens suggestions/advice

Hi,

i only have my E600 kit lens. I am mostly wanting to take pictures of my Son when he is born in July. I am considering the 35mm, 40-150 or at a push if i can possibly find one second hand the 14-54.

I know they are three different types of lenses but i want to know which one will give me the best images/quality of image. With me being an keen beginner i wonder if i would notice the difference between my kit lens and 14-54. Of course iti s a better lens but would i really notice at my level?

I was considering the 35m for the bokeh on portraits but then i find the 40-150 can probably give ample bokeh for my level of skill?

ls am guessing that this wil be my only lens for a while as i wont have spare money once he is born. I guess a possibilty would be to spring for both the 35m and 40-150 or try and get just the 14-54?
Any suggestions or advice greatly appreciated.