it all depends on what you like and who you want to murder.
I love the style of a berserker pure. The upside of a rune pure is you can occasionally find people in higher wilderness(where i like to be) who are wearing more expensive gear which generally takes higher defence level. Those people are very easily disposed of. On the downside, a rune pure takes alot of hard work, especially on questing& you also risk alot.
If you've never made a pure before, definetly go one defence. They're easy to manage, can still be sustainable without a main, and very low risk. 1 defence pking helps alot when learning the tactics to pking. Losing full rune can get old in a heart beat.
If i was the one to decide the destiny of your account, i'd say gmaul range pure just like you decided, the trick would be to have equal range and strength levels. By the time your ready to pk gmaul prices will drop. Run law runes on world 336 to get you started financially.