I'd go with the adjective さびしい it's used for more than just lonely in Japanese. So for example 君と話さなくてさびしい It's lonely not talking to you. That's not how you would say in english, but it makes sense in Japanese (at least to me, but I'm not native). Also the Japanese adjective for "to miss" is 恋しい http://jisho.org/search/koishii

I actually think there is no Japanese word for "to miss". You usually just use the -たい　form, 会いたい for example. So i would just say, 君と話したい。(kimi to hanashitai). This means "I want to talk to you" so it's a big differense. Maybe you could use 懐かしい、(natsukashii) as in nostalgic. 君と話すのは懐かしいです. kimi to hanasu no wa natsukashii desu. "It's nostalgic to talk to you" as in "I get nostalgic when i think about talking with you" I hope this helps!