Hi. I tried to create a gish using the Champion of Corellon prc (to have Elegant strike). Quite feat starved, but it manages to do the "4 attack per round and 9th level spells at level 20.
The build is:
Race: Elf (maybe snow elf from Frostburn to have -2 cha instead of -2 con)
Wizard 8
Swiftblade 3
Dragonslayer 1 (to have armor & weapon prof)
Champion of Corellon 2
Spellsword 1
Abjurant Champion 5
At level 20 we'll have BAB +16 and spells as a 17th level - wizard.
Assuming no flaws, we need UA wizard ACF to take fighter feats. We can use Otyugh Hole for free Iron Will.
1: Dodge, Combat Expertise
3: Mounted Combat
5: Mobility
6: Weapon Finesse
9: Combat Casting, Spring Attack
12: Improved Weapon Familiarity
13: X (bonus fighter feat, with Combat Expertise, Dodge, or Mounted Combat as a prerequisite)
15: free (maybe Practiced Spellcaster to have full CL)
18: free (Arcane Strike could be fitting, since the char is a gish, or even Power Attack if we use an Elven Courtblade to do some nasty combo with wraithstrike)
Without flaws, how can the build be improved? I know that dropping Champion of Corellon could make easier to build a gish, but I'd really like to keep the "Dex on attack & Damage".