Two further observations come to mind, one for each track:
1. A CCNA starts you on the road to Cisco certification and professional education. Indeed, it's a requirement for most Cisco specialist certs and for all Cisco professional certs. But by itself, it's not enough to do you much good in terms of landing new work or a promotion. That's because it's a basic, entry-level exam that doesn't really show much advanced knowledge, skill, or aptitude. If you want to say in networking, you should be thinking about one or more Cisco professional level certs, probably CCNP, and perhaps CCDP or CCSP depending on your longer-term goals.
2. Pursuing MCDBA and MCAD will take time, and mean climbing substantial learning curves. You'll probably have to stick with your net admin job for a year or longer while earning the MCDBA or MCAD, and perhaps even another year to complete that pair of credentials.
Thus, no matter which horn of this dilemma you settle on (networking or DBMS/development) you'll probably need to stay put for as long as two years before you can make any meaningful career moves. This will require some patience, in addition to some substantial time, effort, and outlay as you do the work necessary to make your move.
Good luck with your decision-making and planning efforts. Do feel free to post again if I can provide more input, perspective, or opinion.
This was first published in March 2005