The Blood Spirits would aim for designs that don't require a lot of maintenance to maintain or are easily convertible. Their Omnimechs reflect that. The Crimsom Langur ended up being a joint experiment with the Fire Mandrills which was a fast deviation from the normal no XL based units the Spirits typically favor. The Stooping Hawk is a good example of a Spirit OOmni design. Endo Steel construction, medium speed, solid configs, fixed jump jets for all around mobility.
Other Omni designs they favor are things like the Kingfisher, the Battle Cobra, the Crossbow, or the Nova. Anything that only carries 1 or two weight savings at maximum with efficient amounts of pod space. For second line units that have no current Clan conversions, i suggest the following
Crockett
Thorn
Mercury
Stalker
Crusader
Starslayer
Sentinel
Crab
Ostroc
Hornet (iffy given the Thorn)
Shootist
Kyudo
Catapult
Mackie
Thug
Chameleon
Longbow.
Black Knight
All of these designs use little to no weight saving tech, punch decent or even well above their weight class, and are built to last. They also mostly carry at least one of the Spirit's favorite weapons, the SRM 4, the Large Laser, o the LRM-15.