I'll go out on a limb and say that you're better off making a melee combatant out of an eldritch knight. Far better off. If all you want is to hit with ray/orb spells, you're not getting much out of Eldritch Knight. By 10th level, you've picked up two points of BAB vis a vis a straight class wizard and a couple feats. That will make a small difference in the amount of times you hit. On the other hand, you've also lost two caster levels. That means that, for every empowered scorching ray you cast, a straight-class wizard can cast either a quickened magic missile plus a scorching ray or a maximized scorching ray. Given that, by tenth level, wizards focusing on ranged touch attacks generally don't miss anyway, I don't think trading down to empower for two points of BAB is worth it.
The same is true of summonings. If you pursue that route, you'll be summoning lantern archons and howlers while your single-classed companions summon hound archons and brown bears. Using summonings to hold enemies back for more blasting is just combining two ways to be subpar at once.
In melee, on the other hand, you have a lot more synergy. That synergy can be divided into two sections: games where wraithstrike is allowed and games where it isn't. (IMO, sensible DMs will disallow wraithstrike--it's FAR too powerful for a 2nd level spell and would still be worthwhile at 6th level). In games where wraithstrike is allowed, wraithstrike+Power Attack is really all you need. But, you can tack on some more synergy easily enough. Blink is an excellent defensive spell, but it works wonders for offense as well. Deny your foes their dex bonus and all they have left is deflection (and luck if they have a staff of power or something) when you cast wraithstrike. Arcane Strike a decent spell and you get even more damage. If you have cleave, you'll probably get to do that damage yet again (my 16th level character dropped a Cornugon from full to dead in one round using this trick and followed it up by doing the same to an Angel of Decay in his next game). If you extend the wraithstrike spell, you can make two full attacks and follow the second round up with a quickened whirling blade to get the most attacks possible out of the spell.
Without wraithstrike, you've still got a lot to work with. The dancing blades spell from the spell compendium would be worthwhile at mid levels. A 3rd level spell that gives two attacks at caster level+int bonus for weapon die plus int bonus damage is definitely worth using when your main weapon is only doing a little bit more than that. With blink (eventually greater blink) and arcane strike, you can still get a decent power attack in on most creatures and on the ones you don't, you're still at least as well off as an ordinary fighter. Applying greater magic weapon to your weapons will enable you to focus on enhancements like wounding and sacred without sacrificing plus to hit and damage. Using see invisibility will give you an edge on most fighters (who don't really have a good way to deal with invisible foes). You could also use Phantom steed and make flying lance charges. And, as long as you prepped a solid fog, web, glitterdust, freezing fog, vitriolic sphere (Complete Arcane version--the spell compendium version is pretty useless), etc, you can control the battlefield. And with spells like mass fire shield, you can give your allies a bit of love too.
And of course, there's old standbyes like alter self into troglodyte form for +6 natural armor (and then dragonskin for another +5 if you're high enough level to spend a 3rd level slot on more AC). With shield, you're looking at a pretty impressive AC (especially if you take a one level dip into spellsword and wear a mithral chain shirt).
Finally, if you're a fighter wizard, you almost certainly have the Int for Combat Expertise and Improved Trip. And, you'll notice that ray of enfeeblement and enervation will really make a mess of your enemies' strength checks....
