Lisa III is not a DIY, but why do you need a portable amp anyways?
K701s are power hungry, and I dont recommend any portable amps - Unless you're looking to use K701 as portable headphones.
Look for dedicated home amps such as DIY millet hybrid, BADA PH-12, Woo Audio WA6, or if you have money to spare, Zana Deux. Heed Canamp is pretty good as well.
I agree the K701 needs powerful amplification to sound best, I'm currently using them with a PPAv2 which is a DIY project as well and can be made to be transportable but it's quite large - The PPA Project - it has similar, but not identical design as the LISA III.