How's about starting with any good AK-47 derivative or a properly built AK-74 (InRange, ORF, et al) and proceeding as follows:
1: RSA fire control components along with the new Tapco M249 grip to radically improve shootability.
2: Optics: Either a Kobra EKP-1S-03M or an Ultimak/Aimpoint combo. The latter is more better but, a lot more $.
3: Illumination: A surefire universal 9V light with dead-man and always-on switches, along with the Surefire barrel mount will do the job.
4: Sling: Contact Jeff Orchard at CQB Solutions. He'll fix you up real good and you can even go to your weak side with the right combo.
5: Why do you want more rounds rather than less? Those long magazines aren't for dog poop when un-assing a motor vehicle, aircraft, or boat. And they will really make you look like "that guy" when going prone under a barricade. For 20 round 7.62 see Tapco. For 20 round 5.45, JoeKen will have some soon.
The above should provide you a serviceable tool for interpersonal (or international) conflict resolution.
Luck,
SD