Someone downloading the blockchain shouldn't make your computer unresponsive. If you don't have enough upstream bandwidth, it could make your internet really slow.
If you really want to run one, just use something like this:
https://vpsdime.com/cart.php?a=add&pid=416GB RAM
30GB SSD space
4 vCPU cores
2TB traffic
10Gbps uplink
1x IPv4
OpenVZ/Custom
$7/month
... wouldn't do the annual billing tho, since 30GB won't be enough for a year.