Good choice for 5 players?

Four friends and I are looking around for a game to get into, and Guild Wars came up. But is GW a good choice for 5 players who really only play together?

See, I've been poking around at GW wikis and forums and it looks like there are some signs that GW might not be right for us. We love PvP for example, but it looks like a lot of the PvP modes are for party sizes of 4. Same goes for some PvE from what I can tell. There are areas that have a maximum party size of 4.

So what do you guys think, is there enough content in GW where the 5 of us can stick together?

This might be deemed as heresy but you could always join a group then bugger off to join your friends after all its the result that counts not how you get it

GW is designed for team play. With this in mind it should be a good game for you, providing it suits your gaming tastes, as it is quite different from other MMOs, especially WoW.
And yes, there are areas in PvE that have a party size cap of 4, but only in low lvl areas, otherwise it is 8, and even 12 if you want to try the canthan elite missions. Also theres planty of PvP with parties larger than 4.

Is there such a thing as Team Arena or Random Arena for 5+ per team? This site makes me think there isn't:

http://wiki.guildwars.com/wiki/PvP

So our only option, if we start with Prophecies, is Heroes' Accent and GvG.

Only like the first ~10% of the game has a party size of 4. The odd guy out can easily work by himself. Also, there is nothing to prevent you from going back and doing the mission over with him. In GW there is map travel that allows you to go from point a to point b instantenously once you've gotten there. Therefore, its real easy to get from one point to another to help a friend out.

Or you can simply split into two groups and fill the rest with hench or heroes until you get to the areas with party sizes 6 and up.

And all the other chapters (Factions, Nightfall, EotN), is there any PvE for party sizes <5?

By the way, you guys are very helpful, thanks.

EoTN (or GWEN, as it's popularly known) is meant for level 20 chars, and all the content is for at least 8 peeps.

Both Factions and Nightfall have starting areas of 4, then 6 then 8. But, these starter areas go pretty quickly, and with Heros in Nightfall, there's no reason to team up in the beginning anyway...

In Factions, the party size is only limited to 4 until you get to the eastern side of monastery island. You can easily get there in a matter of hours if you ignore side quests.

Only the beginning of each game has a party size of four, and in the case of Prophecies, a party size of 2.

I think it would be cool for 5 friends to play together.

4 man parties aren't in a huge area of the game, you just gotta do a few missions first.

Keep in mind you can play 8 man areas with 5 people (you can use NPC henchmen and heroes (human customized henchmen)) to fill your party up to fill in the last 3 slots.