Float rods with the reel seat sitting just above the middle of the handle seems to be the norm with many manufacture's choice in producing factory tied float rods & catering to most everyone taking up the sport. Rods however with reels seats further to the top of the handle can't be ruled out, as more commonly noticed on steelhead spinning rods when used with a centerpin reel. Considering the effect to always being in control when float fish/drift the current with a rod and pin ..a longer butt-handle is probably more effective and of more importance rather than more fore grip for best comfort, offsetting the rods tip-heaviness, weight and ease of use. Keeping the reel forward also results to an entire rod-handle at a realistic length, eliminating excessive weight to the rod and less shoulder rests.
When floatfishing ..the reel's position on the handle is the most important aspect of the sport. Controlling the reel's drum on every drift and slowing it down is crucial for success, while at the same time being able to hold your rod/reel together-grasped in your palm's hand comfortably with adequate grasp & hold-power when those "jaw-breaking" strikes that you will never have enough. Not to mention ..also being comfortable to pressure-lock the spool's drum feeling your adversary's every move and power. Its this action using a centerpin reel that makes float fishing so unique, effective and downright addictive. Its truly unmatched ..by any other type of river-fishing or set-up in action and in numbers. However... It can sometimes be hard to grasp and take time to perfect and some even give up.
By getting comfortable with your rod and in full control of your drifts, your bait's speed slows against the natural flow/speed of the river current, giving your bait-a chance to drift down river forward your rigging for best view & presentation to the fish, enticing strikes and more fish to the bank. In reality you will probably never get the the urge to solely grasp the fore grip, therefore rendering it of the least important. Just enough fore grip-length to accommodate and keep your thumb comfortable, rather your full hand probably won't surprise you which is quickly resulting to many spinning rods in the market with quite short fore-grip offering an excellent choice for float reel use as well.
Needless to say though ..the power house rods, especially noted in the west cost fishery may also suite your need if longer than normal handle designs are preferred as in case by many Local & West Coast fishermen drifting high current river systems, commanding high break-strain lines and long fore grips to turn fish around and out of the current. Especially when hooking monster Kings and Wild Steelhead. The drum control however doesn't change... Happy fishing. JM