Little help with additional units

I would like to ask You for little help. Well first of all, I have to say that Pegasus is perfect, and i simply LOVE it. You all did great job and it is probably the best mod for EAW I have ever played. I was very passionate player of the original Stargate at war so You can understand, that Pegasus is like a christmass present for me. But now for my question. I am editing the xml. for adding few units - so far, I added daedalus and aurora for Tauri, Apophis for Goauld and ZPM hive with general for Wraith. It was easy but now, I would like to add more ships into supergates and here is the problem, I do not know where to find the xml of the Supergate, I tought that it is in "specialstructures" but it was not there. Can You please tell me where can I find it? I would like to add all Replicator units as well as Genii, Asuran etc. in order to enjoy them in one gameplay.
The secondary question is, if I can add hero Apollo and Hammond from the original Stargate at War? I am just a little bit nostalgic and want to have as many Tauri heroes, as possible. If it is possible, could you tell me how? I suppose that simple addition of new xml is not sufficient.

Well that would be all, so I want to thank the whole team for this mod and believe me that I am looking forward the next relese.

thank you for your advices. I see now, that adding a new units is probably way beyond my skills so I think i settle for the units already present in the pegasus. As a matter of fact, I have tried it already and it was not as easy as I thougt. I was under the impression, that if I add the name of the unit (for example Ashen battleship) It will be automaticaly there in supergate but it is not. So far, the only unit I was able to add were the asuran corvette an replicator cruiser - both for wraith faction. I have found out, that both of these units hava their "wraith version" same with Grace and Traveler for Tauri and the same for goauld. So here is my question. Can I somehow add default unit to the gate in order to be accesable for all three factions or am I forced to make "faction specified" version of all desired units. Example - Can i made ashen cruiser accesable for Tauri without making new unit - "Unit_Space_Tauri_Aschen_Cruiser"?

Just add "Rebel, Empire, Underworld" in the Faction-Tag for each ship you want to add:)

thanks a lot!!!! . I have already added traveler ship to the gate and it is now accesable by wraith as well .
right now, I want to make all the ships from neutral side accesable to each faction. But it confuses me little bit. If all it takes is to change an <Affiliation>, why are there all neutral units in dual for example "Unit_Space_Ori_Mothership" and "Unit_Space_Goauld_Ori_Mothership" etc

Maybe they have different stats, e.g. the neutral ones have more shield points

All units ready, thanks every one of you

considering this I have to ask, Does AI uses additional /supergate units? I ask because i have not seen them in use by AI so far. Also I have to ask the same thing about Ori Satelite above Celestis. By the way, extremly nice model U suppose that the station should be able to create ori ships, which would be hostile to every faction on the map. but the station is just defending itself. I know that question like that should not be in this topic, but I think it is little pointless to create new topic just for this one question so I am sorry for a little off-topic.