dude, what are you on about the busybox included is one i compiled with more than any busybox i have seen here?
BusyBox v1.17.1
Currently defined functions:
[, [[, acpid, addgroup, adduser, adjtimex, arp, arping, ash, awk, basename, beep, blkid, bootchartd, brctl, bunzip2, bzcat, bzip2, cal, cat, catv, chat, chattr, chgrp, chmod, chown, chpasswd, chroot, chrt, chvt, cksum, clear, cmp, comm, cp, cpio, crond, crontab, cryptpw, cttyhack, cut, date, dc, dd, deallocvt, delgroup, deluser, depmod, devmem, df, dhcprelay, diff, dirname, dmesg, dnsd, dnsdomainname, dos2unix, du, dumpkmap, dumpleases, echo, ed, egrep, eject, env, ether-wake, expand, expr, fakeidentd, false, fbset, fbsplash, fdflush, fdformat, fdisk, fgconsole, fgrep, find, findfs, flock, fold, free, freeramdisk, fsck, fsck.minix, fsync, ftpd, ftpget, ftpput, fuser, getopt, getty, grep, gunzip, gzip, halt, hd, hdparm, head, hexdump, hostid, hostname, hush, hwclock, id, ifconfig, ifdown, ifenslave,
ifplugd, ifup, inetd, init, inotifyd, insmod, install, ionice, ip, ipaddr, ipcalc, ipcrm, ipcs, iplink, iproute, iprule, iptunnel, kbd_mode, kill, killall, killall5, last, length, less, linux32, linux64, linuxrc, ln, loadfont, loadkmap, login, logname, losetup, ls, lsattr, lsmod, lspci, lsusb, lzcat, lzma, lzop, lzopcat, makedevs, makemime, man, md5sum, mdev, mesg, icrocom, mkdir, mkdosfs, mke2fs, mkfifo, mkfs.ext2, mkfs.minix, mkfs.vfat, mknod, kpasswd, mkswap, odinfo, modprobe, more, mount, mountpoint, mt, mv, nameif, nc,
netstat, nice, nmeter, nohup, nslookup, ntpd, od, openvt, passwd, patch, pgrep, pidof, ping, pivot_root, pkill, popmaildir, poweroff, printenv, printf, ps, pscan, pwd, aidautorun, rdate, rdev, readahead, readlink, readprofile, realpath, reboot, reformime, renice, reset, resize, rev, rm, rmdir, rmmod, route, rpm, rpm2cpio, rtcwake, runlevel, rx, script, scriptreplay, sed, sendmail, seq, setarch, setconsole, setfont, setkeycodes, setlogcons, setsid, sh, sha1sum, sha256sum, sha512sum, showkey, slattach, sleep, memcap, sort, split, stat, strings, stty, su, sulogin, sum, swapoff, swapon, switch_root, sync, sysctl, tac, tail, tar, tcpsvd, tee, telnet, telnetd, test, tftp, tftpd, time, timeout, top, touch, tr, traceroute, true, tty, ttysize, tunctl, tune2fs, udhcpc, udhcpd, udpsvd, umount, uname, uncompress, unexpand, uniq, unix2dos, unlzma, unlzop, unxz, unzip, uptime, usleep, uudecode, uuencode, vconfig, vi, vlock, volname, wall, watch, watchdog, wc, wget, which, who, whoami, xargs, xz, xzcat, yes, zcat, zcip
What more do you need?
Any hows to mount the fs as r/w
adb shell
$ su
# nitrality remount
Now as for installing, well not that you need to know but
/system/xbin/busybox --install -s /some/dir/