First knife question

[ks_jon]

I'm about to start on my first knife, but would like some advise. I'm starting with a small one that I would like add to an armguard. My question is what dimensions would make a good knife for that purpose? Any help is appreciated.

[skullworks]

I have done some armguard knives and none are over 5-1/2" total.

[kansas stik man]

oal would have to be short for me and probally either very thin or no scales at all to keep it tucked in tight.