What was available..

[Albiegamer]

Right now I've got our local group staying with the tech available in the Inner Sphere around 3025.  We know that compared to earlier periods lots of tech was lost thanks to war and attrition. All I ask for custom mechs is not using anything that wasn't readily available in 3025, use anything available to make their most evil 'frankemech'.   

We have a few players who are long term Battletech fans and really know the history etc, but most of us don't have that level of knowledge. I've tried looking for a list of what was (or wasn't) available around 3025 but couldn't find anything even slightly definitive, not even on Sarna.net.

Is there any kind of list out there that would help me with my quest?

Thank you,
Al Beddow, Amarillo Texas, Earth Prime, Third Rock From the Sun, Reality #314

[nckestrel]

Hello Al Beddow from Terra!
http://www.masterunitlist.info/
The Master Unit List is a BattleTech resource all about canon units in the BattleTech universe, including what units were available when, and to who.
You can use the Era tab, and then select Late Succession Wars - Renaissance (3020-3049), and then a faction, to see all the units that were available during that time frame to that faction. 
If you mean specifically 3025 (and not just the general era of "3025"), under the Units tab there is a unit search where you can enter it more specific filters, like intro date of 3025 or less.  Note that this can be a bit of a trick question, since the Clans did exist during this time frame, and presumably you don't want to count those in most 3025 era games.  So you'd need to filter them out, such as selecting a specific Inner Sphere faction (as in the initial directions above).

Here's an example filter where I've set it to intro date 1 to 3025, availability era Late Succession Wars - Renaissance (3020-3049), and selected the five major Houses, the general Inner Sphere availability, and mercenaries.

Master Unit List, 3025 filter

[Albiegamer]

Hello Al Beddow from Terra!
http://www.masterunitlist.info

Thank you for that. I hadn't done a deep dive into the MUL, just making a list with varying GS/PS ratings.

But, besides only using what mechs were available in the 3025 time period I'm looking for is specific equipment not specific mechs.  One of our knowledgeable players explained that while the Star League era had double heat sinks, by around 3025 (yes general era around that date, definitely pre/non clan) the ability to build and equip double heat sinks had been lost.

Al Beddow, Amarillo the Yellow Rose, Texas, Earth Prime, Third Rock From the Sun, Reality #314

[Knightmare]

Equipment availability can be found in books like TechManual and Interstellar Operations Alternate Eras . TechManual would provide basic 3025-tech, while IO: AE has additional alternate eras that could add more equipment to a 3025 game. Both books are available in digital format (see links).

Alternatively, you could peruse the various units from TRO 3025 on Sarna for a general idea of what was available during the 3020s. (Clicking through the various TRO units, while tedious, will also answer your equipment question.)