Warhammer 40k titan would be my land vehicle. Specifically the warhound ... Since this is a small engagement. As for my 100 man unit... Let's keep it on the 40k universe. 100 space marines is a space marine company, so 1 space marine battle company. Excluding vehicle and keeping it to 100 men, break down would be. 6 x 10 man squads with bolters 1 special weapon and 1 heavy. 2 x 10 man squad of jump marines (close combat), with 2 special weapons 2x 10 man squad of devastators ( heavy support) armed with bolters and 4 heavy weapons.