Enoonan - my 3 cents - In general, any rod that casts 40gr or over is way to heavy.
Seatrout: any rod capable of casting >25 grs would be considered was too heavy. Somewhere in the range of 5-16gr would be idea. If you're going to be wading, 7 foot is nice, 8 foot would considered too long.
Pollack/bass: Again - really no need for a rod that can cast > 25gr. There are not many hard baits/plugs in this weight category. Most range between 10/18grs. If you're considering spinners/metals, beware there is a point (around 24grs) at which the having extra weight doesn't provide any distance gain. Your far better off choosing a better class of braid (sunline castaway PE 1.0) for the extra distance
If I were you, or me a good few years ago, I would by 3 types of rod UL, L, ML/M
UL = 0.5-5grs - LRF / trout / canal rod. Can be used for Seatrout also
L = 2-10gr - Heavy LRF / Seatrout / Pollack / Mackeral <- you havn't lived till you catch a pollack or mackeral on this class of rod (or even a 7lb seatrout)
ML/M - Depending on the rod length - the casting ranges will vary. A 7 foot would probably overlap a L model, but in general for 8/9 foot rods you'd find that they are around 5-25gr.
Rather than getting just one rod, get 3. Be nice to yourself. You will have more options available to you for your fishing. Over time, you can up grade each rod every xmas/birthday.