Heck you could even respect and try hybrids (for example the poison build has quite a few spare point, so you can run a poison summoner hybrid quite easily, although tbh, corpse explosion works great for summoners without the need for dedicated poison and bone skills). Then if you really want to, you can slowly work your way to endgame gear including Enigmas and the usual uniques every build uses.

You can get the Trang-Oul's set for quite cheap, and it should be enough to clear most of the content. When he starts to have trouble surviving as a Meleemancer, I usually have a big enough army to stand back and use curses and corpse explosions. Personally, I play him as a a Meleemancer for most of Normal and Nigthmare, fighting alongsides his troops and taking out priority targets like the shamans and detonating large groups of monsters with corpse explosions. Heck I quite often make three necros per ladder season since I love each of their playstyles. While I would suggest Summoner, know that both the Poisonmancer and Bonemancer are quite viable and fun too. He's a pretty versatile chracter that's not too gear dependent and can basically work great on all the content, including uber tristram if you gear him properly.

Personally i've always been a Necro fanboy, so I will greatly recommend him.

Diablo 2 best necromancer solo build