I thought to myself instead of forming a party, I'll conjure up my own parties, as i solo a pure summoner. I'm not going to limit myself to just summoning spells, but they will be the main focus.

So I am just wondering which class would make for a better experience in this respect. Not too concerned with powergaming, just what would be more fun.

Any particular thoughts on characters?
Sorcerer
Regular Mage
Wild Mage
Conjurer
Druid
Cleric
Cleric/Ranger

Thanks in advance

I'd say a conjurer or sorc. But be warned, you can only have a max of 5 summons out at once. Yep, that means that as battles start getting tough and you really need your minions, they might not be enough all at once.

That said, with the right summons any battle can go as easy as with a regular party :) . That's actually a very interesting and awesome idea. Good luck with it!

EDIT: Oh yea, conjurer or sorc because they give you the maximum number of spells per-day between the other classes in order to have enough summons/spells for your battles.

That was the only thing really worrying me to be honest. Is there anyway to raise the max summoning cap past 5? Or is that hardcoded?

There is such a way yet it is considered cheese(and even cheating). You may use Projected Images and Simulacrums(for a Ranger/Druid - a Vhailor's helmet). Summoning via PI and Simmys allows you to summon as many as you want monsters. Combined with a long-lasting type of summon, like a Skeleton Warrior, you can actually swarm the place with summons.

A bit of advice - learn the stats/immunities of your different type of summons. For instance, Fire Elementals are immune vs Fire and weapons +1 and lower, and deal Crushing+Fire damage, and have amazingly low strength, and are quite vulnerable to Enchantment spells. So, you may consider casting Strength+Chaotic Commands on them, and send them vs enemies which use fire attacks/spells, like Firkraag for instance, or vs enemies who use +1 and lower weapons, such as Shadow Fiends.

Replace the regular mage in your team either with Conjurer or Invoker, or with a second Sorcerer.

You must avoid useless summoning spells altogether though, lowly monster summons really don't help much, you better prepare other spells instead of them (if you are a wizard) If you are a sorc, good summons start with Spider Spawn at lvl 4, great combo with Web spell so you better have it too! Stay away from monster summonings I, II, III. Animate Dead is a must to have, though it is really not a 'summoning' spell in pure terms.

Elemental summonings are tricky and painful for a mage. Mordenkainen Swords are very useful though. Efreets and Genies are rather a pain than help, IMHO.

Death spell is the bane of all your summons. One mage or lich can cast it and destroy ALL of your summons instantly, leaving you alone and defenseless...beware, keep a wand of summoning ready and use the weaker summons of the wand as cannon fodders for incoming death spells first.

You can go frenzy with Demon summonings as well, just be sure to cast PfE on yourself.
Demons, being gated, do not suffer from Death spell.

Once you get HLAs, Planetars are extremely useful and tough allies, with their great melee capabilities and a wide variety of spells. (which include clerical spells you can not cast!)