Sign me in, I'm available for both PSO and PSO2, (I used to be a GM on the Ultima server, now retired but I still have some goods I can part if you join there)
as for groups of 4.... well it's a bit more complex than that, allow me to explain:
the game just as PSO1 is based on 4 player instances however it can escalate even higher....
Let's say Whiterose makes a room, (password included), and 3 players join that room, Whiterose's party by definition is full and the game
then creates an instance for up to 4 players, however the instance itself is divided into 2 types of areas:
SINGLE-PARTY AREAS
These areas are designed for 4 players max at the same time, some maps are straightforward, some are not, you can view storyline cutscenes here if you wish
or carry on, some SPECIAL events might occur if you have a full party of people at the same time, but once you move to the next area you MIGHT enter this new
place called....
MULTI-PARTY AREAS
These areas are considerably bigger than single-party areas, and can hold 12 players at the same time, a party itself has room for 4 people, but these areas allow
up to 3 full parties to wander around, so basically even if you put a password on your party, you CAN (not always) bump into another group here,
so for example if I want to join Whiterose's party but it's full I can still join her created instance as a second party, we can STILL meet in MP-Areas.
I'll downright say this now..... MP-AREAS are FUN and DANGEROUS XD
you see when you create your instance, you'll select a quest you want to complete, however as you wander through the map, some (randomly selected) events might
trigger... for example... a ship crashes on the ground and you have to protect it for 2 minutes, or in the worst case a BOSS itself is loose on the map
(this is where I believe the game turns into Monster Hunter XD)
MP-AREAS are random. in a nutshell, you never play the same map twice, each time is a different place (save for story missions)
also....
every now and then, the server itself will give you a global announcement all over the game, when this happens it means an [Emergency Quest] is about to begin
EQ's only happen about 4-5 times per day, and give you extra EXP and money (plus rare items), they are meant to be taken by 12 players simultaneously and
by all means could be considered as the game's raids.
here's an example emergency quest: