You're screwed. There is nothing that will satisfy you coming from the K90.
But, my suggestion would be too look at 98 or 100 square-inch racquets. I don't think 5 extra square inches will make that much of a difference to your game. If you're only going to make a tiny change like that you may as well stay with the K90, unless switching to a lighter weight is more important than the headsize.
Your choices will be almost unlimited if you're willing to play around with leadtape: You specified a 9HL balance and balance is the easier spec to change with leadtape. For example, the Volkl C10 Pro is 343grams / 8HL and with 325 swingweight. It is very similar in weight distribution to your K90, but has a 98 square-inch head, about 15 grams less overall weight and a lower swingweight, which means it is easier to swing. It is also legendary for its feel, which is something that many midsize users just can't seem to find in larger sticks. It is also famous for being arm-friendly. And all you'd have to do to get the balance to you liking would be to wrap 3 grams of leadtape around the bottom of the handle, under the grip. Presto.
You should take advantage of TW's demo program, taking out four sticks, and I think the C10 Pro should be one of them. (TW's playtester, Chris, switched to the C10 Pro a while ago. The C10 is about ten years old but they keep making them. Chris tests tons of racquets every year and the fact that he chose the C10 Pro over all these "modern" racquets says something, in my opinion. He also gave this racquet the highest combined score for Power and Feel ever.)
Aside from the C10 I think you should look at several other racquets that are even lighter. Coming from a heavy stick like the K90 you should give a lighter racquet a chance before deciding whether you prefer heavy or light for the long haul. (But my guess is that you will have a hard time choosing a light racquet after getting used to the rock-solid stability and plow of the K90.)
Here are some I would consider:
Boris Becker Delta Core Melbourne (98 ) - discontinued but available cheap
Donnay X Dual Gold (99)
Volkl Organix 10 325 (98 )
Yonex Vcore Tour 97 (97) - comes in a heavy version very similar to the C10 Pro and a lighter version.
Dunlop 4D 300 Tour (98 ) - discontinued but available cheap
Dunlop Biomimetic 200G (98 )
Head IG Prestige MP (95, but such a respected racquet "family" that you might want to try it)
I would also consider trying at least one racquet that has a lighter handle than you're used to. Some people find that removing an ounce of mass from the handle of a racquet makes tennis an easier game to play. The Donnay Pro One (in 16x19 and 18x20) has basically the same specs as the K90 but with about 1 ounce missing from the handle. Weight in the handle doesn't really do anything for you, in terms of power and plowthrough, but it does change the feel of the racquet and how it swings. Some people find that racquets like the Pro One make tennis easier because they can swing these racquets with less effort, especially on serve, but still have all that mass in the head for power and plowthrough. The Pro One looks really nice too.
Last edited by corners; 03-11-2013 at 08:32 AM.