Sorry for the late reply, guys.
Anyway, here's a bit of help...
Sun Caged: Dutch band featuring Marcel Coenen (guitars) and had Joost Van Den Broek (Ayreon, After Forever) on keyboards.
Threshold: Brit band featuring Karl Groom (reknowned producer) and has featured the awesome voices of Damian Wilson (Ayreon) and Andrew McDermott. Band has already 8 studio albums to their active and have been around since the early 90s. Check out their Hypothetical or Dead Reckoning albums.
Karnivool: Criminally unknown Aussie band with only one album so far (Themata) but are quite awesome (especially in vocal department).
DeadSoulTribe: New band of Devon Graves (aka Buddy Lackey of Psychotic Waltz). Prog metal at times mellow, at times edgier, often kinda Tool-sounding. Album to check out: A Murder of Crows.
Poverty's No Crime: Criminally unknown German band (not too much unlike Sieges Even) who are more on the prog side. No famous member but already 6 albums to their active. Great band, especially their last 2 albums. Album to check out: The Chemical Chaos or Save My Soul.
Ice Age: US Prog metal from Long Island (NY). Band only released two great albums in '99 and 2001 before changing names and style. Albums: The Great Divide, Liberation.
Shadow Gallery: US prog metal band. If you like prog and don't know this band, shame on you.

You need to check out this band and their Tyranny album, a masterpiece of prog metal. Also Room V, which is the continuation of Tyranny. Band has 5 albums, no real famous members (maybe Gary Wehrkamp to some) but an awesome vocalist in Mike Baker.
And for the power metal ones... I don't think I need to introduce Pagan's Mind but here's a bit on the others.
Katagory V: USPM band with a bit of prog influences. Good band with 4 albums already. Although I personally am not a fan of USPM, their latest album, Hymns of Dissension, is a worthy listen. Vocalist is an acquired taste, it seems.
Kenziner: A sort of all-star now defunct Finnish band featuring amongst others Stephen Fredrick who did the vocals on the two first Firewind albums and Jarno Koskinen, the mastermind behind the band and also mastermind behind Virtuocity, another neo-classical PM band. Check out their Timescape album.
Eldritch: Italian band who played a wierd thrash metal hybrid on their first 2 albums then verged to thrashy power metal and now turned to progressive power metal. A very good band, especially their last 3 albums. Albums: Portraits of the Abyss Within, Neighborhell, Blackenday.
Serenity: A young but very awesome Austrian band who plays progressive power metal. Only 2 albums so far but quite strong ones. Definitely needs to be known. Got signed to Napalm for their new album, which is a surprise. Albums: Words Untold and Dreams Unlived, Fallen Sanctuary.
Well, that's it... hope all this helps clear up things.
