I have seen a couple of forward cockpit area platforms in person that were very nicely constructed. The construction, as I recall, used a series of closely spaced plank boards, aligned with the fore-and-aft axis of the boat. The planks were about 2-inch width with a gap between them of less than 0.25-inch. The top corner edges of the planks had a slight bevel. The planks were fastened to risers or joists. The forward cockpit area was made level by this platform. The platform extended aft toward the console. I don't recall how the platform and console were arranged. I believe on a 25-foot boat there would be a gap between the platform and the console.
Here is an image from the CETACEA collection (
Cetacea page 53) that shows a platform of the type I just described:
Forward cockpit platform on NAUSETThe general style of these platforms was initiated by Boston Whaler themselves when they made the SAKONNET model. This is not much of an image, but it does show a SAKONNET with the platform:

Most of the nice home-made platforms I have seen have taken their style from the style of the original SAKONNET boats. Those platforms were delivered in a white paint finish, but I think if one uses a quality marine wood like mahogany or teak it would be better to keep the wood finish natural; painting teak would be a bad idea.
Here is another CETACEA collection (
Cetacea page 36) image showing a similar platform installed in an OUTRAGE 21:

If the platform height above the deck is high enough that some useful storage space is created below the platform, then you should incorporate a removable section in the platform to access that storage space below.
If you are always going to cover up the platform with a cushion and it will never been seen, I suppose you construct the platform from less expensive materials than teak or mahogany.