If you swap a K20 in and keep EK subframe the handling is not good due to the engine been to far forward. To do the job right you would want to swap a dc2 subframe in to the EK civic this allows you to use the EKK2 mount's that will position the engine better and also reduce driveshaft angle. Regardless of the niggle's of this swap and the high cost's you just got to love everything about the k20 engine's in a EK or EG chassis the acceleration is unreal so much torque throughout the rev range.
Either you go EKK1 or EKK2, handling goes down(with EK9 ofcourse). With K-series being 10kgs lighter than B-series, it makes up a lil bit.
If you use EKK2 mounts, you need to swap out the Sub frame and steering rack off a DC2R or EG civic(same parts). Not only that, but the complete LCA, knuckle, etc etc off an EG civic. The EK9 subframe is a lot stronger and LCA is 3 times mass bigger. So you end up have the entire front converted with EG/DC2 parts. The EK9 front LCA is also 2 times thicker than DC2R.
EKK1 mounts sit the engine forward more so you dont need to swap out the subframe and keep everything as is, but brings the engine forward about 5cm or 2inches over the EKK2 mounts.
If your building a Track prep car, then you wont mind going EKK2 with the amount of extra work you need. But for a street car or drag car, the EKK1 mounts is much more cost effective and better for Drag cars. Another downfall is the Driveshafts are not aligned as straight, but wont really make much difference on the street.
After comparing my friends (EKK2) EK+K20a sussy/chassis parts etc, its looks pretty damn weak. He was shocked at the size differences between ek9 LCAs, knuckle, sway bar, etc etc. One thing i can say about his setup is, lots of oversteer, especially with that ASR rear brace, LCA kit, rear 4point strut bar etc.
In the end, with the amount of work and changes in mind and the thought of converting my EK9 front end to an EG...I'm going EKK1...