You might wanna check out my 'Delta IV' too, it doesn't use any SRB's but its based on an actual design (hint: look at molo's linked picture and click on mine for the rocket file) She flys wonderfully can achieve both escape velocity and orbit, if I had symmetry she would fly perfectly straight and I would need all those damned SAS's. Very simple rugged two stage rocket really though I do have a version that has a bunch of SRB's strapped on that isn't as 'realistic' but gets it about another 500 m/s of escape velocity. I love simple designs tbh even though I build complicated ones too the simple ones always seem to out perform the ridiculous ones.