What's your budget? Maybe squeeze in some cash for a hub (or whole wheel) that supports a disk, and get a front disk brake. You can get a Shimano front caliper, lever, and hose, assembled and ready to go for ~$65. Shimano front hub... ~30. $40 to lace the new hub.
If it where me, and cash were too tight, I'd upgrade to a front disk first, then upgrade the fork later. You'll have many more options then.
If it where me, and cash were too tight, I'd upgrade to a front disk first, then upgrade the fork later. You'll have many more options then.