I that. Are Kodiaks and Stone Rhinos acquirable by the WiE?
Short Answer: Of course.
Longer Answer: The WiE (last I checked anyway) have access to nearly every unit in the game, Clan or I.S. They trade with the Diamond Sharks and Trial with the Ghost Bears. They salvage from the Jade Falcons and the Word of Blake. They're also with the Lyran Alliance and trade with all the major I.S powers.
I haven't checked the updated MUL as of late, but from the old one and the sourcebooks... like Mechwarrior's Gude to the Clans, the WiE players with a custom 'mech in the RPG (I.e, allowed to pick what 'mech they want) are allowed to pick any I.S unit off the I.S House RATs
or Clan RATs.
The only exceptions, of course, are prototypes and unique 'mechs such as Victor and Hohiro's Direwolves, or things featured in the XTROs.
Widowmaker, however, is an exception to that rule as they've copied Natasha's config and made it official- it's a '12' result on their RAT in one of the books (I think it's Mechwarrior's Guide to the Clans).
They also received alot of the Protomech stuff from the Smoke Jaguar Annihilation, even though they didn't participate.
In short, if it's a canon 'general' config like the Fafnir, Warhammer, Thunderhawk, Kodiak, Blood Kite, Ebon Jaguar C, Warhawk A, Cougar B...whatever, the WiE can use it.
Regardless if it's I.S or Clan.
Well, if you and everyone else want Phelan Wolf to be in this Star, that means this would become the next Golden Keshik, which is a part of the WiE Alpha Galaxy. Although that would be SICK, its not realistic for Phelan to be in a 100 toner. Isn't he used to a Timber Wolf and a Wolfhound? Here's what I'm getting at: I really want this star to be awesome because of its uniqueness, not antireality. I'm saying its more realistic for a bunch a really good mechwarriors to get an ensemble of 100 tonners, than for the Golden Keshik to be completely remodeled and for Phelan to become all of the sudden dissatisfied with his Timber Wolf and bring up a random thought: "I want to pilot a 100 tonner!" You know what I mean?
Phelan used a custom Direwolf for his Trial of Position, and a Nova in the Refusal War. Those aren't the only times he's used other 'mechs too- I want to say he used something different in the Trial with the Jaguars in...
Grave Covenant I think?
In any case, he can use whatever 'mech you want to put him into.
He's never shown the abilities for Phantom Mech, however, as far as I know. His father had it though, which tripled the range against him by all enemies, gave him a constant +10 movement ability, and allowed him to add or subtract 2 from the location rolls against him once per turn.
I.e, Phelan (if he ever had the ability, and he may) could be standing in heavy woods. Enemy A is at 10 hexes away and tries to fire at him with a Gauss Rifle. The range is tripled, so the shot is treated as if he's at range 30. Out of range. Phelan gets to shoot Enemy A as if he's at 10 hexes, however. Enemy B is 4 hexes away and tries to shoot Phelan with a standard I.S Large laser. The range is tripled out to 12, so it goes from +0 (short) to +4 (long). The light woods gives Phelan another +1 bonus, and the Phelan's ability gives him a constant +4 to hit. That means Enemy A has a +9 bonus...unless his piloting is 3 or lower, he can't hit Phelan.
Phelan, however, suffers no such penalties and is a 0/0- so if he was in Widowmaker, for example, to hit Enemy A he needs to roll a 1 on 2D6 to hit the Enemy A at 10 hexes with his ER PPCs and needs to roll a -1 to hit with the Large Pulse lasers.